OK, here’s v3 and v4:

We’re back to melancholy intro music. I shopped around for another ~1m track which hit the right mood, but I couldn’t find a better alternative by Samuel Kim. Other similar ones tend to be too morbid, too military, too synth, or clearly a part of a longer track. I think I’m going to stick with this one for now unless someone shares something amazing.
I have restructured the opening though, hitting the pings in a more balanced way and giving the whole piece more time to breathe and stand alone, and keeping the centred two-page format for the text.
The ending I’ve switched back to the teal colour, but added the movement to the backgrounds. This was quite fun, and I like how it worked out. I think the moving background also makes it easier to parse the text. (Note: I’ve only done these effects for the first four images, since it does take quite a while, just to give you the impression of how it feels.)
The only difference between v3 and v4 is that the intro for v3 goes TCW > Text > Title, and lasts longer, whereas v4 goes Text > TCW > Title, and has a bit less dead time.